The organization and regulation of brain aminergic systems will be investigated along several lines. The induction of tyrosine hydroxylase by reserpine will be characterized, both anatomically and biochemically. Alteration of brain catecholamines by immobilization stress will be characterized in specific brain nuclei. The effects of stress upon behavior with and without drugs will be examined. The interaction of the aminergic and cholinergic systems will be examined by measuring presynaptic and postsynaptic parameters of both systems following a variety of drugs, stress and lesions.